A light emitting element is known having a structure in which a pair of electrodes distinguished as an anode and a cathode sandwich an electroluminescence material. The light emitting element emits light when a certain potential difference is supplied between the anode and the cathode and the intensity of the emitted light can be controlled by the amount of current which flows to the light emitting element.
Display devices formed with a pixel using such a light emitting element are being developed. A driving transistor which controls a current flowing to a light emitting element and a circuit which controls the operation of the driving transistor are further arranged in each pixel. The intensity of the emitted light is controlled by a current value. As a result, it is necessary for the driving transistor to accurately control the current value. The luminosity of the light emitting element is affected and becomes varied between pixels when there is variation in the characteristics of a driving transistor and therefore a technology is necessary to correct this.
In order to correct this, a display device is disclosed in Japanese Laid Open Patent No. 2014-085384 in which a circuit for compensating for characteristic variation of a driving transistor is arranged in each pixel. In addition to a driving transistor which is electrically connected to a light emitting element, a pixel in this display device has a structure which also includes a capacitor element electrically connected between the gate and source of the driving transistor, a switching element which electrically controls a connection between the gate and a signal line, a switching element which electrically controls a connection between the drain of the driving transistor and a high voltage power supply line, and a switching element which electrically controls a connection between the source and a reset signal line.